(1) Field of the Invention
The invention relates in general to antiburst systems for use in water lines, and more particularly, to a pipe section for insertion along a water line for absorbing contraction and expansion when freezing of a water line occurs.
(2) Description of the Prior Art
A major problem in water lines, which are used primarily exterior of a building, is the bursting of the water line when the water therein freezes and expands. Typically, a compressable material is placed inside or adjacent the pipe to prevent the pipe from splitting when the fluid therein expands upon freezing. The material, typically rubber, loses its compressability after a while and no longer functions in the desired manner. Other problems in these devices are that air does not remain entrapped within the sealed rubber tube, but rather seeps away in time, with the result that the tube remains flattened during normal operating temperatures and does not provide the emergency volume needed during freezing. Additionally, when using rubber, it has been found that compression occurs along the diameter of the rubber, while expansion will subsequently occur longitudinally, causing a rupture at a different location in a pipe.
Where it is desired to prevent loss of air in the pipe containing the compressable material, complicated arrangements, such as utilizing an air pump, have been proposed. See, for example, U.S. Pat. No. 3,989,032.
Other known patents include U.S. Pat. Nos. 596,062; 926,092; 2,599,325; 2,629,402; 4,227,512; and 4,308,856.